tests: adjust time_test to fix test failure on some distributions

Result of "import time; print time" can be various from different
distributions, for example:

$ python -c "import time; print time"
<module 'time' from '/usr/lib64/python2.7/lib-dynload/timemodule.so'>

which is diff from the result of "<module 'time' (built-in)>".

So test with result of "print type(time)" instead, which should be
more robust.

test/tests/time_test.py

 import time
-print time
+print type(time)